A magneto-resistive effect element including a magnetic tunnel junction (MTJ) is used in a device such as, for example, a MRAM (Magneto-resistive Random Access Memory) or the like.
When manufacturing a magneto-resistive effect element, a multilayer film is etched. In the etching performed to manufacture the magneto-resistive effect element, plasma of a hydrocarbon gas and an inert gas is generated inside a chamber of a plasma processing apparatus. Ions and radicals generated from the plasma are irradiated to the multilayer film. Thus, the multilayer film is etched. In such etching, a nitrogen gas and a noble gas are used as the inert gas.
When the plasma of the hydrocarbon gas is generated to etch the multilayer film, deposits are formed on the workpiece including the multilayer film. The amount of the deposits should be reduced. As an etching method that makes it possible to reduce the amount of deposits, it is conceivable to use an etching method that alternately performs a step of generating plasma of a hydrocarbon gas and a noble gas for etching of a multilayer film inside a chamber and a step of generating plasma of a hydrogen gas and a nitrogen gas for removing deposits. However, this etching method requires further improvement in suppressing deterioration of magnetic characteristics of a magneto-resistive effect element.